An appropriate balance between soil air and soil water must be maintained since soil air is displaced by soil water. Air can fill soil pores as water drains or is removed from a soil pore by evaporation or root absorption. The network of pores within the soil aerates, or ventilates, the soil. This aeration network becomes blocked when water enters soil pores.
Moissanite (/ËmÉÉªsÉnaÉªt/) is the name given to naturally occurring silicon carbide and to its various crystalline polymorphs. It has the chemical formula SiC and is a rare mineral, discovered by the French chemist Henri Moissan in 1893.
Howlite is a fairly plain looking gemstone that is used extensively in beading. Though it can be seen in jewelry, its main claim to fame is as an imitation of other gemstones. Turquoise, lapis lazuli and coral for example. Natural howlite can look quite good, particularly when used in bead necklaces.